code: def _get_threshold(self):
      # this is a slightly worse model, so we expect it to perform worse
      return 0.5
  
imports: import os
  import pytest
  import unittest
  import parlai.utils.testing
  from parlai.tasks.integration_tests.agents import CandidateTeacher
label_desc: Use image node_id 2 for calling the TestMemNN obj's underlying member method code with example usage: obj._get_threshold() and returns: int